Abstract: A highly oriented thin film of specific barium fluoride materials deposited at low temperatures are useful as Upconversion waveguides.

Abstract: A thin film electroluminescence display element composed of a soda-lime glass substrate having provided thereon a barrier layer including tantalum (V) oxide, a transparent indium-tin oxide (ITO) electrode as a first electrode, a first insulating layer, a luminescent layer, a second insulating layer, and a second electrode is disclosed. The tantalum (V) oxide barrier layer effectively prevents sodium in the soda-lime glass substrate from diffusing into the ITO transparent electrode.

Abstract: An electroluminescent device having a hole injection electrode, an electron injection electrode, and at least an organic emitting layer therebetween, said organic emitting layer includes an 8-quinolinol derivative-metal complex whose ligand is selected from the group consisting of chemical formulas 102 through 106:chemical formula 102 ##STR1## chemical formula 103 ##STR2## chemical formula 104 ##STR3## chemical formula 105 ##STR4## chemical formula 106 ##STR5##

Abstract: There is disclosed an EL element having at least one layer made from an organic material between an electron injection electrode and a hole injection electrode. The organic material consists of an oxadiazole series compound which has a plurality of oxadiazole rings, each of the oxadiazole rings being substituted by a condensed polycyclic aromatic group.

Abstract: A multi-color TFEL display includes a low ohm metal assist structure in electrical contact with the transparent electrodes to improve display brightness, and a light absorbing dark layer to increase display contrast.

Abstract: An AC thin film electroluminescent display panel includes a metal assist structure formed on and in electrical contact over each transparent electrode, and a light absorbing dark layer which combine to provide a sunlight viewable display panel.

Abstract: A thin film electroluminescence device and a process for production thereof. This device is characterized in that as a light emitting layer material or charge injection layer material, a polymer film having at least one of a light emitting layer function, a charge transport function and a charge injection function, and having a film thickness of not more than 0.5 .mu.m is prepared by the vacuum evaporation method and used.

Abstract: An organic thin film electroluminescence element is disclosed. It comprises an organic compound represented by formula I in a luminescent layer or electron injection layer. The element may further comprises a compound represented by formula II in a hole injection layer. ##STR1## The definition is detailed in the description. The element has a greater intensity of luminescence and a high durability.

Abstract: There is disclosed an electroluminescent (EL) element having an electron injection electrode, a hole injection electrode, and at least one layer therebetween, the layer comprising either a Rhodamine metal complex, a chromone metal complex, an azomethine metal complex, or another metal complex whose ligand is either thiobromine, flaviosin, or acriflavine.

Abstract: An improved dielectric layer of an electroluminescent laminate, and method of preparation are provided. The dielectric layer is formed as a thick layer from a ceramic material to provide:a dielectric strength greater than about 1.0.times.10.sup.6 V/m;a dielectric constant such that the ratio of the dielectric constant of the dielectric material to that of the phosphor layer is greater than about 50:1;a thickness such that the ratio of the thickness of the dielectric layer to that of the phosphor layer is in the range of about 20:1 to 500:1; anda surface adjacent the phosphor layer which is compatible with the phosphor layer and sufficiently smooth that the phosphor layer illuminates generally uniformly at a given excitation voltage.The invention also provides for electrical connection of an electroluminescent laminate to voltage driving circuity with through hole technology. The invention also extends to laser scribing the transparent conductor lines of an electroluminescent laminate.

Abstract: Disclosed are organic EL elements having high environmental stability as well as high luminous efficiency and luminance. In an organic EL element comprising a transparent anode, a hole-carrying layer, a light-emitting layer and an alloy cathode consisting of a first metal Li and a stabilizing second metal Al, all laminated on a substrate, the concentration of the first metal Li contained in the alloy region with a predetermined thickness from the interface between the alloy cathode and the organic layer is controlled to a minute amount ranging from 0.005 wt. % to 0.3 wt. %.

Abstract: A radiographic phosphor panel having binder compatible oxosulfur stabilizer and a preparation method. The phosphor panel has a support and a luminescent layer overlaying the support. The luminescent layer includes phosphor crystals, binder and an oxosulfur reducing agent. The oxosulfur reducing agent is dispersed within the luminescent layer on a substantially molecular basis. The oxosulfur reducing agent is a reducing agent for iodine. The oxosulfur reducing agent has a concentration sufficient to substantially increase the photostimulated luminescence of the panel.

Abstract: A photostimulable phosphor of which the emission intensity at the stimulation wavelength of 550 nm is higher than the emission intensity at the stimulation wavelength of 600 nm, characterized in that said phosphor is a divalent europium activated barium fluorobromide containing as codopant samarium, and wherein the terminology barium fluorobromide stands for an empirical formula wherein (1) a minor part of the barium (less than 50 atom %) is replaced optionally by at least one metal selected from the group consisting of a monovalent alkali metal, a divalent alkaline earth metal other than barium, and a trivalent metal selected from the group consisting of Al, Ga, In, Tl, Sb, Bi, Y, and a rare earth metal selected from the group consisting of Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, (2) a minor part (less than 50 atom %) of the bromine is replaced by chlorine, and/or iodine, and (3) wherein fluorine is present stoichiometrically in a larger atom % than bromine taken alone or bromine combined with chlorin

Abstract: Disclosed is a red-emitting organic electroluminescent device comprising in sequence an anode, an organic hole injecting and transporting zone, a doped luminescent zone, an electron transport zone and a cathode, characterized in that said doped luminescent zone is comprised of a fluorescent phthalocyanine compound capable of emitting a wavelength in the range of 660 to 780 nm.

Abstract: Coatings which protect the skin of hypersonic flight vehicles are disclosed. Silicide coatings, such as R512E, is used to minimize catalytic recombination of dissociated species, such as atomic oxygen and atomic nitrogen, thus, decreasing thermal and oxidative degradation. Prehydrated, polymerized sol of tetraethylorthosilicate is applied to a coating, and is fired, to produce an integral protective coating.

Abstract: A radiation sensitized paper having a polyester film, a coating layer which contains a water-soluble or water-dispersible resin and is formed on a surface of the polyester film, a resin layer which is formed on the coating layer and a fluorescent material layer which is formed on the resin layer, in which adhesion of the fluorescent material layer is good.

Abstract: Yttrium-containing phosphors can be stabilized for use in an aqueous slurry containing a binder, which slurry can be used for coating fluorescent lamps by treating with ammonium dihydrogen phosphate and ammonium hydrogen difluoride to inactivate free yttrium ions. The resulting aqueous slurry is stable and provides coated fluorescent lamps having uniform coatings that are bright and long lasting.

Abstract: A europium-doped barium fluorohalide photostimulable phosphor comprises an amount of oxygen sufficient to create a concentration of anion vacancies effective to substantially increase the stored photostimulable energy, compared to a non-oxygen-treated phosphor.

Abstract: An organic electroluminescent device having an organic emitting layer and a hole transport layer laminated with each other and arranged between a cathode and an anode, and the hole transport layer is made of tris-phenothiazinyl-triphenylamine or tris-phenoxazinyl-triphenylamine derivative. The hole transport layer has a high heat-resistant property and high conductivity to improve durability and emits light at a high luminance and a high efficiency upon application of a low voltage.

Abstract: A process for the vapor phase deposition of a fluoride containing glass on a substrate, the said fluoride containing glass containing in mole percent with a total of 100%, 30-50 PbF.sub.2, 30-50 GaF.sub.3, 0-30 ZnF.sub.2, 1-5 MF.sub.2 wherein M is Mn or Cd, 1-5 InF.sub.3, 0-10 AlF.sub.3 and 0-10 adjuvant, which involves contacting the substrate with vapors emanating from a molten bath of metallic fluorides comprising a reception bath containing in mole percent with a total of 100%, 9-26 YF.sub.3, 19-38 BaF.sub.2, 35-40 InF.sub.3, 18-25 M'Fe.sub.2 wherein M' is Mn, Cal or Zn and 0-10 adjuvant to which reception bath has been added a sufficient amount of a mixture of PbF.sub.2, GaF.sub.3 and optionally AlF.sub.3. The invention also concerns a vitreous composition deposited on a substrate, thus obtained, which is useful as a waveguide in the infrared.

Abstract: Disclosed is an electroluminescent element comprising an anode, a cathode and, disposed therebetween, an organic luminescent layer comprising a mixture of a fluorescent luminescent agent, at least one hole moving and donating agent capable of moving holes and donating the same to the luminescent agent and at least one electron moving and donating agent capable of moving electrons and donating the same to the luminescent agent. In the element, the components of the luminescent layer have specific oxidation potential and reduction potential relationships. The element emits light in response to electrical signals. The element exhibits high luminescence efficiency and brightness even at low voltages, and it can efficiently be produced at low cost.

Abstract: Yttrium-containing phosphors can be stabilized for use in an aqueous slurry containing a binder, which slurry can be used for coating fluorescent lamps by treating with ammonium dihydrogen phosphate and ammonium hydrogen difluoride to inactivate free yttrium ions. The resulting aqueous slurry is stable and provides coated fluorescent lamps having uniform coatings that are bright and long lasting.

Abstract: A method for manufacturing a phosphor screen used in a color CRT takes the steps of multilayering a red phosphor layer, a green phosphor layer, a blue phosphor layer, and a non-luminescent layer being laid between the adjacent color phosphor layer, cutting the multilayered block into filmy pieces toward the thickness, adhering or pressurizing the filmy cut pieces on a glass plate for front panel of the color CRT, and burning the cut pieces. This method makes it possible to efficiently manufacture a high-definition and high-resolution color phosphor screen and form fine RGB stripes. This method, thus, may apply to a small-sized CRT about which the realization of the high-definition and high-resolution color phosphor screen has been difficult.

Abstract: A method of preparing a pigment-coated phosphor is provided which comprises the steps of:(a) preparing a pigment dispersion by adding pigment particles in an amount of 0.05 to 10% by weight, based on the amount of phosphor, to one of (i) a solution comprising adipic acid in the range of 0.05 to 2% by weight, based on the amount f phosphor, or (ii) a solution comprising 1,6-hexanediamine in the range of 0.05 to 2%, based on the amount of phosphor, and(b) mixing the pigment dispersion with the other of the solutions not used to form the pigment dispersion and with a phosphor dispersion comprising a phosphor dispersed in distilled water to form a pigment-coated phosphor. A pigment coated phosphor prepared according to this method is also provided.

Abstract: An organic thin film electroluminescent device is composed of an electron transport layer, a hole transport layer and a transparent electrode. The electron transport layer is constituted of an electron conducting polymer represented by the formula (I) ##STR1## wherein R.sup.1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R.sup.2 is a hydrogen atom, an alkyl or alkoxy group having 1 to 4 carbon atoms, an aryl group, an aryloxy group, a thioether group, an amino group, a halogen atom, an aldehyde group, a cyano group, a nitro group or a hydroxyl group, x is an integer of 1 to 6, on the condition that, if x is an integer of 2 to 6, R.sup.2 may be the same or different, and n is an integer not less than 2.

Abstract: A europium-doped barium fluorohalide photostimulable phosphor comprises an amount of oxygen sufficient to create a concentration of anion vacancies effective to substantially increase the stored photostimulable energy, compared to a non-oxygen-treated phosphor.

Abstract: A divalent europium activated alkaline earth metal halide phosphor having the formula (I):M.sup.II X.sub.2 .multidot.aM.sup.II X'.sub.2 .multidot.bA:xEu.sup.2+(I)in which M.sup.II is at least one alkaline earth metal selected from the group consisting of Ba, Sr and Ca; each of X and X' is at least one halogen selected from the group consisting of Cl, Br and I, and X.noteq.X'; A is a compound selected from the group consisting of SiO and SnX".sub.2 wherein X" is at least one halogen selected from the group consisting of F, Cl, Br and I; a and x are numbers satisfying the conditions of 0.1.ltoreq.a.ltoreq.10.0 and 0<x.ltoreq.0.2, respectively; and b is a number satisfying the conditions of 0<b.ltoreq.3.times.10.sup.-2 in the case of A being SiO and 0<b.ltoreq.10.sup.-3 in the case of A being SnX".sub.2.

Abstract: In an electroluminescent panel comprising transparent and back electrode members opposite to each other and an electroluminescent laminate block between the transparent and the back electrode members, a fluororesin layer is coated on the electroluminescent laminate block together with the back electrode member so as to prevent invasion of moisture into the electroluminescent laminate block. The fluororesin layer has a thickness not thinner than 500 angstroms and may be formed by a fluororesin selected from a group consisting of polytetrafluoroethylene, polychlorofluoroethylene, polyvinylidene fluoride, and trifluoroethylene.

Abstract: An improved X-ray intensifying screen comprising phosphor crystals having an effective amount of a light scattering particulate material, e.g., barium sulfate, strontium sulfate, calcium sulfate, titanium dioxide or magnesium oxide, adhered thereto is described. This screen will give high speed and yield an image with increased sharpness when exposed with a single-side coated medical X-ray film element, compared to one made without the particulate material.

Abstract: An electroluminescent element comprising an electroluminescent (EL) material part which emits a near ultraviolet ray of light and a fluorescent material part which absorbs the ultraviolet light emitted from the electroluminescent material and emits a fluorescence in a visible light range from blue to red. The electroluminescent element provides for emission of lights with a wide range of wavelength and three elementary colors of blue, green and red can be expressed by appropriate combinations of the organic EL material and the fluorescent material. Consequently, the electroluminescent element provides for a full color display.

Abstract: Disclosed herein is an electroluminescent device having a luminescent layer comprising a luminescent material, which is capable of directly converting the energy of electric field applied thereto into a light energy and capable of providing a large surface-area luminescence.

Abstract: A phosphor for an X-ray intensifying screen contains a phosphor mixture of a phosphor represented by BaFBr:mEu.sup.2+ (5.times.10.sup.-4 .ltoreq.m.ltoreq.5.times.10.sup.-2), and a phosphor represented by Y.sub.1-2/3.times. M.sup.x TaO.sub.4 :nNb (10.sup.-5 .ltoreq..times..ltoreq.1, 0.ltoreq.n.ltoreq.0.05, and M is at least one member selected from the group consisting of Ca, Sr, and Cd). An X-ray intensifying screen includes a support and a phosphor layer formed on the support and containing the above phosphor. When this X-ray intensifying screen is used, an X-ray image producing less crossover light and having high graininess and sharpness can be obtained. An exposure amount of an object to be examined can be reduced in medical radiophotography, and radiation diagnostic performance can be improved.

Abstract: A divalent europium activated complex halide phosphor having the formula:Me.sup.II FX.multidot.aMe.sup.I X'.multidot.bMe'.sup.II X".sub.2 .multidot.cMe.sup.III X"'.sub.3 .multidot.dA:eEu.sup.2+in which Me.sup.II is at least one alkaline earth metal selected from the group consisting of Ba, Sr and Ca; Me.sup.I is at least one alkali metal selected from the group consisting of Li, Na, K, Rb and Cs; Me'.sup.II is at least one divalent metal selected from the group consisting of Be and Mg; Me.sup.III is at least one trivalent metal selected from the group consisting of Al, Ga, In and Tl; A is a metal oxide; X is at least one halogen selected from the group consistingo of Cl, Br and I; each of X', X" and X"' is at least one halogen selected from the group consisting of F, Cl, Br and I; a, b and c are numbers satisfying the conditions of 0.ltoreq.a.ltoreq.10.sup.-2, 0.ltoreq.b.ltoreq.10.sup.-2, 0.ltoreq.c.ltoreq.10.sup.-2, and a+b+c.gtoreq.10.sup.-6 ; and d and e are numbers satisfying the conditions of 0.ltoreq.d.

Abstract: An improved X-ray intensifying screen element containing a topcoat layer comprising an acrylonitrile-styrene copolymer optionally mixed with a carboxylated acrylic polymer and an active, phosphor layer having an adhesion promoting amount of a soluble, inorganic salt as described. The improved element exhibits strong adhesion between the topcoat and active layers and is eminently suitable for the rough handling encountered when these elements are used in autochangers and the like.

Abstract: There is disclosed a novel cerium activated rare earth oxyhalide phosphor which has the following formula (I):LnOX:xCe (I)in which Ln is Y, La, Gd or Lu; X is Cl, Br or I; and x is 0<x.ltoreq.0.2, and a ratio of X/Ln is 0.500<X/Ln.ltoreq.0.998 by atomic ratio, and the maximum peak (.lambda.) of the stimulation spectrum of the phosphor is 550 nm<.lambda.<700 nm. a radiation image recording and reproducing method and a radiation image storage panel employing the above-mentioned phosphor are also disclosed.

Abstract: A thin film electroluminescent element has a substrate, a transparent electrode formed on the substrate, a luminescent film wherein two kinds of luminescent centers are distributed in layers within a basic luminescent material, formed on the transparent electrode through an insulating film, and a back electrode formed on the luminescent film through another insulating film. The luminescent film of this thin film electroluminescent element can emit white light of excellent tone, including lights of three primary colors with sufficiently large luminous intensity.

Abstract: A radiation image storage panel comprising a support and a phosphor layer provided thereon which comprises a binder and a stimulable phosphor dispersed therein, characterized in that a light-reflecting layer containing a white pigment is provided between the support and the phosphor layer and that said light-reflecting layer is colored with a colorant capable of absorbing a portion of stimulating rays for the stimulable phosphor.

Abstract: A radiation image recording and reproducing method comprising the steps of exposing a stimulable phosphor containing a bivalent europium activated complex halide phosphor represented by the formula:BaFX.xNaX':aEu.sup.2+wherein X and X' each designated at least one of Cl, Br and I, x is a number satisfying 0<x.ltoreq.10.sup.-1, and "a" is a number satisfying 0<a.ltoreq.0.2, to a radiation passing through an object to have the radiation energy stored in said stimulable phosphor, stimulating said stimulable phosphor by an electromagnetic wave having a wavelength within the range of 450 nm to 1,100 nm, thereby causing said stimulable phosphor to emit said radiation energy in the form of light, and detecting the emitted light.

Abstract: An electronic system having a first printed wiring board, a first integrated circuit carrier positionable on the printed wiring board and a substrate having a central portion formed of ceramic material. The substrate central portion has a specific thermal conductivity greater than 1.5.times.10.sup.-5 Wm.sup.2 /g.degree.C. The substrate may comprise a ceramic material formed in combination with a modifier of the type which increases fracture toughness thereby inhibiting crack initiation and growth. In an alternate form of the invention the elctronic system includes a substrate having a central portion formed of ceramic material and first and second opposing surfaces each clad with a metallic layer of predetermined thickness.

Abstract: Blue-luminescing lanthanum-gadolinium-oxybromide, activated by trivalent cerium, which oxybromide is also activated by trivalent terbium and is defined by the molecular formulaLa.sub.1-x-y-z Gd.sub.x Ce.sub.y Tb.sub.z OBr,in which0.25.ltoreq.x.ltoreq.1-y-z,0.002.ltoreq.y.ltoreq.0.05,0.0001.ltoreq.z.ltoreq.0.005 and y.ltoreq.z.

Abstract: An ultrafine grain fluorescent body comprises an ultrafine grain luminescent material containing an activator and having a surface carrying thereon a layer which is formed from a different material from the luminescent material, or which has different properties from those of the luminescent material. The layer forms a heterojunction or p-n junction defining a luminescent mechanism in an interface between the luminescent material and the layer. The heterojunction is formed if the layer is a film of oxide, nitride or any other different substance formed on the surface of the luminescent material, e.g. ZnS, having a grain size of several hundred to several thousand angstroms. Alternatively, the p-n junction is formed if the luminescent material is a p-type (or n-type) semiconductor, and if the layer is a film of an n-type (or p-type) a semiconductor formed on the surface thereof.

Abstract: A divalent europium activated alkaline earth metal halide phosphor which is coactivated with boron and has the formula (I):M.sup.II X.sub.2.aM.sup.II X'.sub.2 :xEu.sup.2+,yB (I)in which M.sup.II is at least one alkaline earth metal selected from the group consisting of Ba, Sr and Ca; each of X and X' is at least one halogen selected from the group consisting of Cl, Br and I, and X.noteq.X'; and a, x and y are numbers satisfying the conditions of 0.1.ltoreq.a.ltoreq.10.0, 0<x.ltoreq.0.2 and 2.times.10.sup.-4 .ltoreq.y.ltoreq.2.times.10.sup.-1, respectively. A radiation image recording and reproducing method utilizing said phosphor and a radiation image storage panel employing said phosphor are also disclosed.

Abstract: A radiation image recording and reproducing method comprising steps of:(i) causing a divalent europium activated complex halide phosphor having the formula (I):M.sup.II X.sub.2 .multidot.aM.sup.II X'.sub.2 .multidot.bMgX".sub.2 :xEu.sup.2+ (I)in which M.sup.II is at least one alkaline earth metal selected from the group consisting of Ba, Sr and Ca; each of X and X' is at least one halogen selected from the group consisting of Cl, Br and I, and X.noteq.X'; X" is at least one halogen selected from the group consisting of F, Cl, Br and I; and a, B and x are numbers satisfying the conditions of 0.1.ltoreq.a.ltoreq.10.0, 2.times.10.sup.-5 .ltoreq.b.ltoreq.2.times.10.sup.-2 and O<x.ltoreq.0.2, respectively, to absorb a radiation having passed through an object or having radiated form an object;(ii) exposing said stimulable phosphor to an electromagnetic wave having a wavelength within the range of 450-1000 nm to release the radiation energy stored therein as light emission; and(iii) detecting the emitted light.

Abstract: A divalent europium activated complex halide phosphor having the formula (I):M.sup.II X.sub.2.aM.sup.I X':xEu.sup.2+ (I)in which M.sup.II is at least one alkaline earth metal selected from the group consisting of Ba, Sr and Ca; M.sup.I is at least one alkali metal selected from the group consisting of Li, Rb and Cs; each of X and X' is at least one halogen selected from the group consisting of Cl, Br and I; and a and x are numbers satisfying the conditions of 0.1.ltoreq.a.ltoreq.20.0 and 0<x<0.2, respectively. A process for the preparation of said phosphor, a radiation image recording and reproducing method utilizing said phosphor, and a radiation image storage panel employing said phosphor are also disclosed.

Abstract: Photoluminescent materials useful for detection of infrared light are prepared using a base material, first and second dopants and a fusible salt. The base material is an alkaline earth metal sulfide such as calcium sulfide. Lithium fluoride is used to enhance the interdiffusion of materials. Samarium and a europium compound are used as the first and second dopants for providing electron traps. The photoluminescent material is made according to a process involving heating of the material to a fusing temperature, grinding the material after cooling, and reheating the material to below the fusing temperature, but sufficiently high to repair the crystal surfaces. The material is then placed in a transparent binder and applied to a substrate, or deposited as a thin film directly on a substrate for different uses.

Abstract: An electroluminescent device comprising an electroluminescent layer capable of emitting light under application of AC voltage, the electroluminescent layer comprising strontium sulfide as a matrix and containing at least one of halides and sulfides of cerium, europium, thulium, terbium and samarium, and having a lattice constant of not more than 6.04 .ANG. and a half-width value at the (111) face of not more than 0.21 degree has a higher brightness than an electroluminescent device having an electroluminescent layer comprising ZnS as a matrix.

Abstract: A divalent europium activated alkaline earth metal halide phosphor having the formula (I):M.sup.II X.sub.2 .multidot.aM.sup.II X'.sub.2 .multidot.bA:xEu.sup.2+(I)in which M.sup.II is at least one alkaline earth metal selected from the group consisting of Ba, Sr and Ca; each of X and X' is at least one halogen selected from the group consisting of Cl, Br and I, and X.noteq.X'; A is at least one oxide selected from the group consisting of SiO.sub.2 and P.sub.2 O.sub.5 ; and a, b and x are numbers satisfying the conditions of 0.1.ltoreq.a.ltoreq.10.0, 10.sup.-4 .ltoreq.b.ltoreq.2.times.10.sup.-1 and 0<x.ltoreq.0.2, respectively. A radiation image recording and reproducing method utilizing said phosphor and a radiation image storage panel employing said phosphor are also disclosed.

Abstract: A phosphor material for a radiation intensifying screen includes phosphor particles which emit light upon radiation excitation, and alkaline-earth metal fluoride. The alkaline-earth metal fluoride is formed in situ on the surface of the phosphor particles through a reaction of a first reactant containing the alkaline-earth metal with a second reactant containing the fluoride to improve the dispersibility of the phosphor particles. The phosphor material is dispersed in a binder and coated on a base support as a phosphor layer to provide a radiation intensifying screen.

Abstract: A gradient radiation image conversion sheet, comprising a protective layer a fluorescent layer and a support layer, and the transmissions of said protective layer and/or said fluorescent layer are partially changed and the dots of the print of said gradient patterns and the border between the printed area and the unprinted area are blurred. The gradient image conversion sheet has a gradation area in which the change in transmission is extremely smooth and a speed ratio which may be set in a relatively wide range, and the sheet can be produced through a mass-production system to give products of constant quality.

Abstract: Photoluminescent materials useful for detection of infrared light are prepared using a base material, first and second dopants and a fusible salt. The base material is an alkaline earth metal sulfide such as calcium sulfide. Lithium fluoride is used to enhance the interdiffusion of materials. Samarium and cerium sulfide are used as the first and second dopants for providing electron traps. The photoluminescent material is made according to a process involving heating of the material to a fusing temperature, grinding the material after cooling, and reheating the material to below the fusing temperature, but sufficiently high to repair the crystal surfaces. The material is then placed in a transparent binder and applied to a substrate, or deposited as a thin film directly on a substrate for different uses.